Orthopaedic surgeons are regularly required to cut bone and other hard tissue during surgical procedures. To achieve this, surgeons usually make use of powered tools, such as sagittal saws. A typical powered saw has a handpiece and a blade mount in which a surgical blade may be secured. The handpiece usually houses either an electrically or pneumatically driven motor. The motor drives the blade mount which, in turn drives the saw blade. The saw blades are usually removably coupled to the blade mount such that they may be replaced. This is particularly important for surgical saws due to the need to sterilise any tools which are used during a surgical procedure. However, due to the need to accommodate additional space within the mount to allow the blade to be easily slid in and out, as well as the necessary manufacturing tolerances resulting from fabrication of the parts, the blades cannot be fit perfectly to the blade mount. This may result in movement between the mount and the blade causing the mount to wear down through repeated use.
Two varieties of powered saws are sagittal saws and reciprocating saws. Sagittal saws drive the blade mount to rotate side to side. This oscillatory rotation results in sagittal saw blades pivoting about one end of the blade which is secured within the blade mount. A cutting edge, such as a serrated edge, is located at the distal end of the blade, running across the width of the blade. Reciprocating saws are driven to oscillate in line with the length of the blade. A cutting edge is located on one or more of the side edges running down the length of the blade.
Typically surgical saws use flat saw blades which are secured at a coupling portion at one end. The coupling portion of a sagittal saw blade usually comprises slots or openings into which coupling members, such as pins, may be received in order to secure the blade to a blade mount. In addition to these pins, the blade may be clamped against the base of the blade mount to secure it in place. Quick release mechanisms are available which allow for blades to be easily disengaged from blade mounts without the need for tools.
Due to the nature of the oscillatory action of a sagittal saw there is a large amount of force applied at the points of contact between the blade and the mount, particularly when the blade is changing direction. Due to the excess space within the blade mount, the blade may rub or strike surfaces of the blade mount, causing both the blade and the mount to wear. As the surfaces wear down, the blade may work loose therefore becoming less efficient and resulting in a less stable support for the blade. The excess movement of the blade within the mount may cause vibrations resulting in the blade cutting less accurately and causing noise which may be distracting to the surgeon. The reduced accuracy and stability of the saw and blade may increase operation times. There is therefore a need for a blade mount and corresponding blade which reduce mechanical play during operation and which accommodate for wear through repeated use.